The opsonization of C. albicans by means of sera treated with chloroform and ethyl ether resulted in significantly decreased values of PMN leucocyte phagocytic activity. In contrast to ethyl ether treated sera (decrease of phagocytic activity about 45%), chloroform processed sera possessed increased antiphagocytic activity (decrease of phagocytic activity about 63%). Significant changes were observed in the candidacidal capacity to C. albicans (decrease about 50%) and in the capacity of NBT (INT) reduction measured spectrophotometrically (decrease about 66% in chloroform treated sera and about 42% in ethyl ether treated sera). (Fig. 1, Ref. 22.)